Photographic printing machine



June 14,1932. AS -HOWELL 1,863,051

PHOTOGRAPHI C PRINTING MACHINE Filed July 9, 1929 8 Sheets-Sheet 1 June 14, 1932. s, HQWELL 1,863,051

' PHOTOGRAPHIC PRINTING MACHINE Filed July 9. 1929 8 Sheets-Sheet 2 A. s. HOWELL 1,863,051

PHOTOGRAPHIG PRINTING MACHINE June 14,, 1932.

Filed July 9, 1929 8 Sheets-Sheet 3 &

June 14, 1932 A. s. HOWELL 1,353,051

PHOTOGRAPHIG PRINTING MACHINE Filed July 9, 1929 8 Sheets-Sheet 4 Eden??? 1.66)? 6. 0%]! W Q jw June 14, A s HQWELL PHOTOGRAPHIC PRINTING MACHINE 7 Filed July 9. 1929 8 Sheets-Shegt 5 Nr//// 4 w\\\\ W Mf/M;

June 14; 1932. v HOWELL 1,863,051

PHOTOGRAPHIC PRINTING MACHINE June 14, A. HOWELL PHOTOGRAPHIC PRINTING MACHINE 8 Sheets-Sheet 7 Filed July 9. 1929 June l4, 1932.. l a HOWELL 1,863,051

PHOTOGRAPHIC PRINTING MACHINE Filed July 9, 1929 8 Sheets-Sheet 8 15 42 If #3 ms l/ W //i w liq/f fi e b? 1 v2 7 'l #3, g j I \D J Um ZHEQE q O p d 2 7/8 c i4 2 g 2; Q jhferzzzr dim)? o? 921K617 wa wal Patented June 14, i1 932 UNITED STATES PATENT) OFFICE ALBERT S. HOWELL, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE BELL & HOWELL GOM- IPANY, OF CHICAGO,'ILLINOIS, A (.7OIFLPJRAEIIION' OF ILLINOIS rnorroenarmc PRINTING macnmn Application filed July 9,

My invention relates particularly to motion picture film printing machines although not limited to this use alone.

The general object of my invention resides in the provision of an efiicient and convenient photographic printing machine which is adapted for the independent and variable exposure of different sections of an unexposed photographic element progressively, say for the independent and variable exposure of different longitudinal sections of an unexposed positive motion picture film progressively therealong, and particularly for the printing of a motion picture and a ,re-

' lated visual sound record upon the positive film, and all with a. view toward the use of relatively Wide film, say 70 mm.

The above object and certain other objects, hereinafter appearing, are embodied in the preferred form of my'invention, hereinafter fully described and illustrated in the accompanying drawings, and are effected by certam novel constructions, combinations and arrangements of parts particularly pointed out in the appended claims.

In the said drawings- Figure 1 is a front elevation of a motion picture film printing machine embodying my invention;

Figure 2 is an enlarged partial view in similar elevation with parts broken away;

" Figure 3 is an enlarged partial section on the line 3-3 of Figure l;

Figure 4 is a partial section substantially on the line *"4: of Figure 3 Figure 5 is an enlarged partial section on the line 55 of Figure 4;

Figure 6 is an enlarged the line 6-6 of Figure 3 Figure 7 is a wiring diagram of the electrical exposure controlling system. of the machine;

Figure 8 is an enlarged intermediate sectional view in side elevation of a portion of the machine;

- Figure .9 is an enlarged partial section on the line 9-9 of Figure 10; g FigurelO is a top plansectional view of a portion of the machine;

Figure 11 is a plan view of one of the film partial section on 1929. Serial No. 376,947.

trolled circuit breaker mechanism of the machine; and Figure 14 is a partial section on the line 14-14 of Figure 1.

Likecharacters of reference indicate like parts in the several views.

Referring to the drawings, 1 designates a pedestal which supports the machine, and arranged at the top of this pedestal is a lamp chamber 2 in which is interchangeably mounted, by means of a suitable socket 3, an incandescent electric lamp lof the concentrated filament type. See Figures 1, 3 and t.

A portion of the frame of the machine at the side of the lamp chamber is bored horizontally in a forwardly and rearwardly extending direction, as designated at 5, and communicates radially with the lamp chamber through a light passage 6. See Figures 3,4 and 6. The front end of the bore 5 is closed by a cover member 7 secured on the. frame, and the rear end of this bore is closed by a member 8 also secured with the frame. See Figure 3.

Disposed in the bore 5 in coaxial relation therewith is a revolu bly mounted film feed sprocket comprising two axially spaced peripherally toothed wheels 9 secured on a shaft 11 extending through axial bores through these wheels and extending through and journaled ina central bore throughthe member 8 and having secured thereon immediately to v the rear of the member 8 a gear 12 by means of which this shaft is driven. See Figure 3. The light passage 6 is alined with the plane of the'space between the wheels 9, and the frame is provided with an opening communicating with the bore 5 between the wheels 9 and disposed in substantially diametrically opposite relation with respect to the light passage 6. See Figures 3, 4 and 6. A motion picture film guide is associated with this opening and consists as follows. A pair of stationary film face guide platen I I 13 are mounted on the frame and extend in said opening in opposite tangential relation with the wheels 9 and have their adjacent ends spaced.

The adjacent ends of the plates 13 are extended in the following manner;

An arcuate member 14 is secured against the surface of the bore 5 between the wheels 9 and extends the upper end of the lower plate 13. SeeFigures 3, 4 and 6.

Another arcuate member 15 is secured against the surface of the bore 5 between the wheels 9, see Figure 4, and extends the lower end of the upper plate 13 except for a relatively narrow portion adjacent the inner wheel 9 which portion is extended by a third arcuate member 16, see Figure 6.

An opposing film face guide member 17 is mounted on a pivoted arm 18 for movement into and out of film guiding relation with the guide plates 13 extended by the arcuate members 14, 15 and 16, this guide member being so mounted to open the guide for thelacing and unlacing of film therein and to form with the plates 13 extended by the arcuate members 14, 15 and 16, when it is in film guiding relation therewith, a film guide for retaining film therein engagement with the sprocket comprising the wheels 9.

Accordingly, the intermediate portion of the guiding face" of the guide member 17 is of concave form corresponding with the periphery of the sprocket comprising the wheels 9, and the end portions of this face are tangent thereto in correspondence with the disposition of the plates 13. The guide member 17 is releasably secured in film guiding position in a manner unnecessary to be described. I p

The arcuate members 15 and 16 are spaced from the arcuate member 14 to form an exposure aperture in the guide and facing in' wardly of the wheels 9 for'exposure of film in the guide to light from the lamp 4 and passing between the wheels. See Figures 4 and 6. x

The lower arcuate member 14 is fixed as is the upper arcuate member 16, while the arcuate member 15 is adjustably positioned angular'ly' of the wheels 9 to vary the exposure opening of the guide, with the exception of that portion corresponding with the arcuate member 16, by means of headed screws 19 passing downwardly through the frame in radial relation with the bore 5 and r through angular slots 21 through the arcuate member 15, and screw-threaded into a block 22 off the inside of this arcuate member to secu re the same in angularly adjusted pos\i tion. See Figure 4.

- The guide above referred to is adapted to guide superposed Eprinting or negative and unexposed or positive motion picture films, respectively designated at 23 and 24, engaged on the sprocket comprising the wheels 9, for

the eeding of these films in printing relation it through the guide and past the exposure aperture between the wheels 9 where they are subjected to the printing light provided by the lamp 4 in the lamp chamber 2.

In order that the printing light be uniformly concentrated at the exposure aperture of the guide, a condensing lens isAinterposed between the lamp 4 and the exposure aperture of the guide and is disposed in the light passage 6. See Figures 3, 4, and 6.

This condensing lens consists of two planoconvex lenses 25 having "sphero-cylindrical opposing surfaces 26 disposed with the cylindrical axes thereof extending transversely of the guide in order to provide a desired printing light across the relatively wide exposure aperture of the guide.

The lenses 25 are carried in a suitable mounting 27 having an extension 28 engaging on the bottom surface of the light passage 6 and secured thereto by means of headed screws 29, passing through slots 30 through the extension and screwthreaded into the frame of the machine, the slots being enlarged at corresponding ends to facilitate removal and installation of the condensing lens.

The plane surface of the lens 25 nearest the guide is ground, as designated at 31, for the diffusion of the light, and transversely spaced vertical opaque strips 32 are disposed immediately in front of this surface and serve as light modifiers and aid in effecting a uniform light across the exposure aperture of the guide.

Thus, a desired printing light is provided across the exposure aperture, it being noted that the guide and its exposure aperture are relatively wide for the printing of relatively wide film, say mm.

I As beforeimentioned the lamp 4 is of the concentrated filament type, and is adjustable alongthe focal axis of the condensing lens in the following manner. and 5.

The socket 3 is mounted on,a base33 which See Figures 3, 4

is slidably mounted, as designated at 34, on a plate 35secured at the bottom of the lamp chamber 2 with the slide portion thereof parallel to the focal axis of the condensing lens. Thus the'socket and lamp 4 mounted thereon are adjustable along the focal axis of the condensing lens. 1

A vertically slotted lug 36 is secured on the socket 3 by .means of a clamp band 37. A

screw 38 is screwthreaded through the wall ed thereon are adjustable along the focal axis screw 43 is engaged on the screw 38 within .the lamp chamber and a lock mit 44 is engaged on this screw onthe outside of the lamp chamber for securing the screw in the desired position, the screw being provided with an exterior'manipulating knob 45.

In order that different longitudinal sections of the films in the guide may be exposed independently and variably the following is provided. See Figures 3, 4and 6'.

A vertically disposed partition member 46 is disposed between the wheels 9 and. adjacent the inner wheel- 9, and the inner side of this member is channeled, as designated at 47, corresponding with the passage of the printing light between the wheels 9 to provide a light passage to the exposure aperture of the guide and corresponding in' width and alined with the arcuate member 16, herelight passage, a U-shaped strap 51 embracing the sprocket shaft 11 to light trap the opening through the member 46 and plate 48 necessitated by the shaft.

Thus the exposure aperture of the exposure .guide is divided transversely for the'independent exposure of different longitudinal sections of the film in the guide, the outer or wider section of the exposure aperture corresponding in width with that of the arcuate member 15 and the inner or narrow section corresponding in width with that of the channel 47 of the partition member 46. r

The partition member 46 and plate 49 are secured together and with the arcuate member. 14 whereby they are stationary.

Angular adjustment of the arcuate meinof the member 46 and the plate '49 is a shutter lever 52 which is pivoted adjacent the shaft 11, as designated at 53, and extends therefrom to .the film in the guide with its free end which varies the inner or narrow portion of the exposure aperture of the guide as it is. adjusted angularly. A spring54 yioldably urges the free end of theshutter lever downp p wardly to decrease the corresponding portion of the exposure aperture, and a screw stud 55 is screwtln'eaded through the arcuate member 16 and, passing through a bore through the member 46 engages a radial lug 56 on the lever 52 for cooperation with the spring 54 to adjustably position the shutter lever 52.

These adjustments of the different portions of the exposure aperture of the guide are provided formore or less permanentadjustment, and in order to provide for the in dependent and variable adjustment of the exposure of the di ti'crent sections of the film during the printing operation additional adjustlnentmeans are provided which will now be described.

The forward end of the sprocket shaft 11 extends through a coaxial bore through the cover member 7 and is journaled in a sleeve 57 which in turn is journaled in the said bore through the cover member 7, thus providing 7 a bearing for the front end of the shaft 11 and providing for angular movement of the sleeve 57. See Figure-3.

Secured on the inner end of the sleeve-57 within the bore 5 is an arm 58 at the free end of which is mounted an arcuate shutter 59 which, clearing the, periphery of the outer wheel 9, extends rearwardly to the partition portion 48 so that adjustment of this shutter by angular movement of the sleeve 57 effects adjustment of the amount of printing light passing between the outer wheel 9 and partition portion 48 to the corresponding portion of the exposure aperture of the guide with resulting adjustment of the exposureof the corresponding portion of the film in v the xfguide. See Figures 3 and 4.

A lever 61 is secured on'the sleeve 57 for 62 is pivoted on the lever 61 at an intermediate point thereon. See Figure 2. Another lever 63 is pivoted on the front of the cover member 7 in coaxial relation'with the lever 61 and extends in front of the lamp chamber 2, its free end terminating in a gear segment 64'.

an index dial 65 at the rear of which is a revoluble gear pinion 66 disposed in coaxial relation with the dial and meshing with the segment 64. Secured with the gear pinion 65 and disposed in front of the dial is an operating lever 67, one end of which co-operates iwithv an index scale 68 on the front of the dial to indicate the several positions of the lever and the other end of which is provided Carried'in front of the lamp'chamber 2 is with a knob 69 associated with mechanism,

ward upon a cam roller 73 mounted on a. downward intermediate extension 74 of the lever 63, and a spring device, generally indicated at 75, reacting on the lever 63 yieldably urges the arm downwardly to effect actuation of the cam 72 upon the cam roller 7 3 into a predetermined position with respect thereto, that is, in the position in which the 'cam roller is engaged in the angle of the cam.

The movement of the arm 62 resulting from such action effects corresponding adjustment of the lever 61 and corresponding adjustment of the shutter 59.

Pivotal adjustment of the lever 63 by manipulation of the operating lever 67, operating through the gear pinion 56 meshing with the gear segment 64, effects a change of positionof the cam roller 73 with resulting adjustment of the shutter 59.

A rod 76 is pivoted to the lever 61' and extends horizontally in front of the lamp chamber 2. Disposed below this rod in front of the lamp chamber is an electromagnet 77 which is provided with an armature 78 pivoted at 79 on an axis transverse to the rod 70 and yieldably urged and maintained in its normal position by means of a spring device 81. 4

In its said normal position the armature 78 engages the rod 76, in a manner corresponding with a similar mechanism hereinafter described, and secures it against longitudinal movement thereby locking the lever 61- and consequently the shutter 59 against movement.

When the lever 61 is so locked, movement of the lever 63 by operation of the operating lever 67 to another position merely operates the cam roller 73 out of its predetermined position at the angle of the cam 72.

After such operation ofthe lever 07,- energization of the electromagnet 7 7 attracts the armature 78 against the influence of the spring device 81, whereupon the rod 76 is released and the spring device 75 operates the cam 72 on the cam roller 7 3' so that the roller is positioned in the angle thereof, this resulting in adjustment of the shutter 59 in an obvious manner. Upon deenergization of the electromagnet 77 the spring device 81 operates the armature 78 to its normal position and thus locks the shutter 59 in its adjusted position. I

- A shutter mechanism, generally similar to that just described, is provided for controlling the exposure of the-portion of the film in. the guidecorresponding with the channel 47- and will now be described.

A shutter rod 82 is mounted for longitudinal reciprocation'in the frame of the machine and is disposed so that its upper end portion is movable across the channel 4:7

adjacent the condensing lens to vary the.

printing light passing through this channel through the rod 82 and embracing a stud 85 on the rod and extending across said slot whereby pivotal movement of this lever effects longitudinal movement of the rod.

Another lever 80 is pivoted at one end, as designated at 87 and has its free end terminating in a'gear segment 88. Carried on the frame of the machine is a second dial 89, and journaled on the frame in coaxial relation with the dial is a shaft 91 upon the inner end of which is formed a gear pinion 92 meshing with the gear segment 88.

Secured on the outer end of the shaft 91 in front of the dial 89 is an operating lever 93, one end of which co-operates with an index scale 94; on the front of this dialto indicate the several positions of the lever and the other end of which is provided with a manipulating knob 95 mounted on the outer end of a plunger 96 slidably mounted in a.

bored bushing 97 on the lever for engagement and disengagement of the inner reduced end thereof with holes 98 in the face of the dial 89 for releasably locking the lever 93 in different positions thereof, a spring 99 yieldably urging the plunger 96 into engagement with the holes 98 and the knob 95 being pulled outwardly to disengage the plunger from the holes 98.

An internal V-shaped cam 101 is pivoted, as designated at 102, on the lever 86 intermediate the ends of this lever, and this cam engagesa stud 103 on the intermediate portion of the lever 83. A spring 104 reacting on the lever 86 yieldably urges the cam 101 upon the stud 103 to effect actuation of this stud into a predetermined position with respect to this cam, that is in the position in -which the stud is engaged in the angle of the cam. 4 The movementof the lever 86 resulting from such action efiects corresponding adjustment of the shutter rod 82.

Pivotal adjustment of the lever 86 by manipulation of the operating lever 93, operating throughthe gear pinion 92 meshing with the gear segment 88, effects a change of position of the cam 101 with resulting adjustment of the shutter rod 82.

z Pivotally mounted on an axis transverse to the shutter rod 82, asdesignated at 105, is a locking member 106 through an aperture of which passes the shutter rod. See Figures 6, 9 and 10; A spring 107 maintains this locking member. in its normal position, as'

illustrated, in whichthe locking member cramps the shutter rod 82 and looks it against ti'oiezd armature'78 acts with respect to the r 6.

An enlarged free end 108 of the member 106 forms the armature of an electromagnet 109 mounted on the frame of the machine, and when energized this electromagnet at tracts the armature portion 108 of the member 106 against the influenceof the ring 107, into the position indicated by broken lines in Figure 9, andreleases the shutter rod 82 for adjustment thereof. 2

When the shutter rod 82 is locked, as above described, movement of the lever 86 by operation of the operating lever 93 to another position merely operates the cam 101 out of its predetermined relation with the stud 102 in which the stud is disposed in the angle of the cam.

After such operation of the lever 93, ener- 2 gization of the electromagnet 109 attracts the armature portion 108 of the member 106 against the influence of the spring 107, whereupon the shutter rod 82 is released and the spring 104 operates the cam 101 on the stud 103 so that the stud is positioned in the angle thereof, this resulting in adjustment of the shutter rod 82 in an obvious manner. Upon de-energization of the electromagnet 109 the spring 1.07 operates the member 106 to its normal position and thus locks the shutter rod in its adjusted position.

In order that adjustment of the shutter 59 and the shutter rod 82 may be effected independently at predetermined points during the printing operation for varying predeterminat-ely and independently the exposure of the corresponding sections of the film without interrupting the printing operation the following is provided which functions in conjunction with the hereinbefore described devices for adjusting the shutter 59 and the shutter rod 82.

The negative film 23 is trained over a revolub'le roller 111 in its passage to .the ex- I posure guide hereinabove described See Figv ures 1 and 12. Mounted on the frame of the machine adjacent this roller are two circuit breakers 112 of an enclosed contact type, each of which includes a pivoted member 113 carrying contacts 114 for movement into and out of contact with stationary contacts 115 and a spring 116 yieldably urging the pivoted member into a position to engage the contacts 114 and 115. See Figures 11 and 12.

The pivoted members 113 are provided with radial arms 117 which extend outwardly of the enclosures of the circuit breakers through suitable openings in the enclosures thereof and the outer ends of these radial arms are provided with revoluble anti-friction rollers 118. j The circuit breakers 112 are so mounted that the rollers 118 thereof have rolh'ng contact with he edges of the negative film 23 at the roller 111 and so that the edges the respective e adjacent edges of a card therein for vertiof this film normally maintain the circuit breakers open against the influence of the springs 116. See Figures 12and 13.

The circuit breakers are closed when the rollers 118 enga e in notches 119 formed in dges of the negative film at points corresponding with desired exposure light changes durin the printing operation as hereinafter described. I

Mounted on the upper portion of the lamp chamber 2 is a card holder comprising a vertically disposed plate 121 and parallel vertical guides 122 at the vertical edges of the plate and a card supporting ledge 123 at the bottom edge of the plate adapted to have an index card 124 interchangeably mounted thereon. See Figures 1 and 14.

Slidably mounted in suitable guides 125 on the rear of the plate 121 are two vertically disposed ratchet bars 126 disposed adjacent respective vertical edgesof the card holder and these bars are provided with indicators 127 extending therefrom about the vertical edges of the card holder and in front of the cally traversing the card in the holder with vertical movement of the respective ratchet bars.

Each guide 125 is provided'with a rearwardly projecting tubular formation in which is mounted an electl'omagnet 128. An escapement pawl 129 is provided for each ratchet bar and is pivoted intermediate its ends and is provided with a tooth 131 at its upper end and a tooth 132 adjacent its lower end. The upper tooth 131 of each pawl is kept normally in engagement with the teeth of its ratchet bar 126 by a suitable spring 133 that presses against the lower end of each pawl. See Figure 14.

The upper portion of each pawl is positioned adjacent the core of its electromagnet 128 so that when the latter is ener ized the pawl will be attracted thereto thus isengag-. ing the tooth 131 from the ratchet bar and permitting the same to drop and be caught or held by the, lower tooth 132.

This operation is repeated as often as each electromagnet 128 is energized and de-energized thus causing the corresponding indi-.[ 115 cator 127 to vertically traverse, step by step,

' the card 124 on the holder.

Referring to Figure 7, one of the circuit breakers 112 is connected in series with both the electromagnet'7 7 and one ofthe electromagnets 128, so that each time that this circuit breaker is closed and opened by engagement and disengagement of the roller 118 thereof with a notch 119 in the corresponding edge of the negative film 23 during the feedi thereof, the electromagnet 77 is energiz d and de-energized to release the shutter 59 for adjustment thereof corresponding with a previous adjustment of the operating lever 67 and to lock the same in adjusted pcsition, and the corresponding electromagnet 126 is energized and de-energized for effecting a step movement of the corresponding 1n dicator 127 to indicate on the card 124 the responding edge of the negative film 23 during the feeding thereof, the electromagnet 109 is energized and de-energized to release the shutter rod 82 for adjustment thereof corresponding with a previous adjustment of the operating lever 93 and to lock the same in adjusted position, and the corresponding electromagnet 128 is energized and de-energized for effecting a step movement of the corresponding indicator 127 to indicate on the card 124 the next adjustment of this shutter rod, as hereinafter described. The index card 124, as shown, is an interchangeable form card upon which have been placed various notations arranged in succession vertically, including notations 134 arranged adjacent the'path of one of the indicators 127 to indicate, in co-operation with the hereinbefore described step by step move-.

ment of this indicator, each adjustment of say the shutter 59 as it is to be made during the printing operation, and including notations 135 arranged adjacent the path of the other indicator 127 to indicate, inco-operation with the hereinbefore described step by step movement of this indicator, each adjustment of say'the shutter rod 82 as it is to be made during the printing operation.

-These notations 134 and 135 on the card 124 are the same as the notations on the scales 68 and 94 of the dials 65 and 89 so that the operating levers 67 and 93 may" bereadily adjusted in correspondence thereto. In the operation of the machine the operating levers 67 and 93 are positioned corresponding with the notations on the card 124- indicated by the indicators 127. When either circuit breaker112 closes and opens, the shutter 59 or shutter rod 82, as the case may be, is adjusted, as hereinbefore described, and the corresponding indicator 127 is moved to the next notation on the card whereupon the operator adjusts the operate ing lever 67 or 93, as the case may be, to the position corresponding with the indicated notation preparatory to the next opening and closing of the corresponding circuit breaker.

This procedure is continued through the printing operation, thus providing for the independent and predeterminate varying of the exposure of the different longitudinal-sections of the film at predetermined points during the printing operation, preferably without interrupting the printing operation. -'The invention has particular relation to. the printing of a motion picture and a related visual sound record upon the positive film 24. Accordingly, referring to Figure 13, the negative film 23 is provided with a relatively wide motion, picture bearing longitudinal section 136 corresponding in width and alined with that portion of the exposure aperture of the exposure guide between the light separating partition portion 48 and the outer wheel 9, controlled by the shutter the hollow core of the electromagnet 109 and terminates at its lower end in an external ring 139 for manipulatiomto release'the shutter rod 82 instead of by energization of the electromagnet 109. See Figures 8 and 9.

.When such manual control is used, .the circuit including the electromagnet 1'09 and the corresponding electromagnet 128 and circuit breaker 112 may be opened by a'suitable switch 140. See Figure 7.

Disposed at the rear of the bore 5 of the frame and extending upwardly and downwardly-therefrom is a gear casing 141, see Figure 1, in which is enclosed a gear train, not shown, includingthe gear 12 on the sprocket shaft 11, as shown in Figure 3.

Referring again to Figure 1, revoluble film feed sprockets 142 and 143 are mounted on the gear casing 141 respectively above and below the exposure guide and are driven in timed relation with the sprocket comprising the wheels 9 by the aforementioned gear train which is driven by a suitable motor, not shown.

The negative film 23 is fed from an upwardly disposed feed spool 144by the upper sprocket 142, thence about a tensioning roller 145, thence about the roller 111, and thence through the exposure guide where it is fed by the sprocket com rising the wheels, 9. After passin througi the exposure. guide, the negative hlm is fed by the lower sprocket 143 to a downwardly disposed take up spool 146'wl1ich is driven to wind this film thereon in a usual manner. unnecessary to be described.

The positive film 24 is fed from an upwardly disposed feed spool 147 by the upper sprocket 142, thence about a tensioning roller 148, thence about a roller 149, and thence through the exposure guide where it is fed in superposed printing relation with the negative film 23 bythe sprocket comprising the wheels 9. After passing through the exposure guide, the positive film is fed by the lower sprocket 143 to a downwardly disposed take up spool 151 which is driven to wind this film thereon in a usual manner unnecessary to be described.

WhileI have herein shown and particularly described the preferred embodiment of my invention I do not wish to be limited to the precise details of construction shown as changes may readily be made without departing from the spirit of my invention, but having thus described my invention, I claim as new and desire to secure by Letters Patent the following:

1. In a motion picture film printing machinethe combination with a revoluble film feed sprocket, comprising two axially spaced wheels, and a film guide disposed for guiding superposed films engaged on said sprocket and exposure apertured between said wheels and inwardly thereof, of a single source of printing light, a lightseparating partition between said wheels for subjecting independently, in said guide, different longitudinal sections of said films to light from said source and passing between said wheels, and shutter devices for varying independently the ex-' posure of said sections to said source.

2. In a photographic printing machine the combination with an exposure apertured film guide, an incandescent electric lamp of the concentrated filament type providing a source of printing light, and a condensing lens interposed between said guide and lamp and comprising a pair of plano-convex lenses having sphero-cylindrical opposing surfaces and disposed with the cylindrical axes thereof extending transversely of said guide, the plane surface of one of said lenses being ground for light diffusion.

In a photgraphic printing machine the combination with an exposure apertured film guide, a source of printing light, a condensing lens interposed between said guide and said source and comprising a pair of lenses "having convex sphero-cylindrical opposing surfaces and disposed with the cylindrical axes thereof extending transversely of said guide, and means between said condensing lens andfilm in said guide for "varying independently the exposure of different longitudinal sections of said film to light passing through said condenser from said light source.

4. In a photographic printing machine the combination with an exposure apertured film guide, an incandescent electric lamp of the concentrated filament type providing a source of printing light, a. condensing lens interposed between said guide and said lamp and comprising a pair of plano-convex lenses having sphere-cylindrical opposlng surfaces and in said disposed with the c lindrical axes thereof extending transverse y of said guide and having the plane surface of one of said lenses ground for the diffusion of light, a light separating partition extending between said guide and said condensing lens andseparating the light from said source transversely of said guide, and independently adjustable shutters for varying the exposure of portions of film guide .on respective sides of said partition. J

5. In a photographic printing machine the combination with an exposure apertured film guide, an incandescent electric lamp base for the mounting of a lamp therein to provide a source of printing light, a condensing lens interposed between said guide and lamp and comprising apair of plano convex lenses having sphero-cylindrical opposing surfaces and disposed with the cylindrical axes thereof extending transversely of said guide, the plane surface of the lens nearest said guide being ground for light diffusion, and means for ad- Justin said lamp base along the path of v combination with an exposure apertured film guide, a source of printing light, a condensing lens interposed between said guide and light source and comprising a pair of lenses having convex sphere-cylindrical opposing surfaces and disposed with the cylindrical axes thereof extending transversely of the guide, the other surface of one of said lenses being ground for light diffusion, and opaque light modifying members associated with said condensing lens and extending longitudinally and spaced transversely of said guide.

7. Ina motion picture film printing machine the combination with a revolnble film feed sprocket, comprising two axially spaced wheels, and a film guide disposed for guiding superposed films engaged on said sprocket and exposure apertured between said wheels and inwardly thereof, a condensing lens comprising a pair of lenses having convex spherocylindrical opposing surfaces and disposed with the cylindrical axes extending transversely of said guide for-condensing printing light passing therethrough and between said wheels to said guide, and means between said condensing lens and said films in said guide for varying independently the exposure of different longitudinal sections of said films to said printing light.

chine the combination with a revoluble film feed sprocket, comprising two axially spaced wheels, and a film guide disposed for guiding superposed films engaged on said sprocket and exposure apertured between said wheels "and inwardly thereof, a'condensing lens comprising a pair of Plano-convex lenses having sphero-cylindrlcal opposing surfaces and disposed with the cylindrical axes thereof extending transversely of said guideior con-.

9. In a photographic printing machine thecombination with a reciprocable light shutter of a releasable device for locking the same in adjusted position, a pivoted lever for operating said light shutter, a manually adjusted member movable correspondingly with said lever, a V-shaped cam member movably mounted on said manually adjusted member for actuating said lever in either direction into a' predetermined position with respect thereto, and spring means yieldably urging said cam member in a direction to actuate said lever upon release of said releasable device.

10. In a photographic printing machine the combination with a longitudinally re- -ciprocable light shutter rod, of a member pivoted transversely of said rod for locking said rod in adjusted position and releasing the same, a pivoted lever connected at its free end with said rod for operating the same, a manually adjusted member pivoted correspondingly with said lever, a V-shaped cam member pivotally mounted on said manually adjusted member for actuating'said lever in either direction, and spring means yieldably urging said cam member in a direction to actuate said lever upon release of said locking member.

11. In a photographic printing machine the combination with a longitudinally reciprocable light shutter rod, of a member pivoted transversely of said rod and having an opening through which said rod extends for locking said rod in adjusted position and adapted for release of the rod, a spring normally maintaining said locking member in locking position, electroresponsive means for operating said locking member to release said rod, a manually adjusted member, a V-shaped cam member movably mounted on said manually adjusted member for actuating said rod in either direction into a predetermined position with respect thereto, and a spring yieldably urging said cam member in a direction to actuate said rod upon release of said locking member.

12. In a photographic printing machine the combination with means for exposing an unexposed photographic element in printing relation with a photographicprinting element progressively, of devices for varying independently the exposure of different sections of said unexposed element,me'ans under the control of the printing element whereby said exposure varying devices are actuated independently at predetermined.points dur ing the printing operation for varying predeterminately and independently the exposure of said sections, a single record member I bearing data as to the changes of exposure of said sections, and means under the control of said printing element for indicating progressively the said changes of exposure in' timed relation therewith.

13. In a motion picture film printing machine the combination with means for ex'posing an unexposed photographic film in printing relation with a printing film progressive ly therealong, of devices for varying independently the exposure of different longitudinal sections of the unexposed film, devices independently under the control of said printing film whereby said exposure varying devices are actuated independently at predetermined points during the printing operation for varying predeterminately and independently exposure of said sections of the unexposed film Without interrupting the printing operation, an interchangeable single record member bearing data as to the exposure of said sections, and devices under the control of said printing film for indicating progressively on said record member the said changes of exposure in timed relation therewith.

14. In a motion picture film printing machine the combination with means for exposing an unexposed film in printing relation with a printing fihn progressively therealong,

of devices for varying independently the exently the exposure of said sections of the un-. exposed film without interrupting the printing operation, an interchangeable record card bearing data asto the exposure of said sections. and electroresponsive devices under the control of the printing film for indicating progressively on said record card the said changes of exposure and in timed relation therewith. v

15. In a motion picture film printing machine the combination with means for exposing an unexposed positive film in superposed printing relation with a negative printing film progressively therealong including a single exposure guide, of shutter devices for varying independently the exposure ofdifierent longitudinal sections of the films in said guide, electroresponsive devices under the control of notches in respective of the edges of the negative film whereby said shutter devices are actuated independently at predetermined points during the printing operation for varying predeterminately and mdependently the exposure of said sections of 5 the films without interrupting the printing operation, an interchangeable record card bearing data as to the exposure of said sections, and electroresponsive devices also under the control of said notches in respective of the edges of the negative film for indicating progressively 'on said record card the said chalillges of exposure in timed relation therewit In witness whereof I hereunto afiix my 15 signature this 1st day of Jul 1929.

ALBERT HOWELL. 

